01 ALH intermittent no start issue.

Having an issue with my jetta where it will intermittently not start. Been reading through this http://forums.tdiclub.com/showthread.php?t=199398 but not finding the issue.


I have:
*Replaced the fuel filter.
*Replaced the 109 relay.
*Manually ran 12v to the solenoid to confirm it clicks.
*Confirmed the anti shutter valve moves freely and last time it didn't start I tried wedging it open with a stick with no affect.
*I have applied vacuum to the pump return line while plugging the inlet to make sure I had no leaks at the pump or injector lines.
*Applied vacuum at the tank inlet to make sure I could pull fuel. Two pumps with the mighty vac had fuel coming out the line.

I have a new T coming but am not sure mine even leaks, I will give that a test today. Last night it did this again almost stranding my on a trailhead. I had the mightyvac and pulled fuel through the return line, didnt make a difference. What finally got the car started was stepping on the accelerator while cranking it over. Once it is running it seems fine and I am not getting an CEL. I'm scratching my head on what to try next. Any help is much appreciated.

Did you crack the injectors while someone is cranking the car to ensure the air is purged out of your injector lines? Sounds like air is getting in the system somehow...

I don't really have anyone to help me unfortunately.

Next time it's in no start mode, try loosening 1 injector, rags, crank maybe 5 seconds. Re-tighten and see if it dont' start right up. If it does, you have a small air leak somewhere.

Is there some other place I should apply vacuum to test for leaks other then the fuel return line?

All the fuel system. Easiest to do one section at a time. The new tee and o rings is a likely. Usually if you get leakage, you get a consistent no start. If it does it mostly after sitting a bit longer, air leak more likely.

Cranks OK, but does not start, correct? Does it only happen after the car has been sitting for a while? Once started and running, can you shut it off and start it right back up? Is it consistent?

My guess from your description is loss of fuel prime. I would examine the system for leaks, especially at or around the pump itself. If it is the least bit wet, anywhere, it is leaking. And that can let air IN, which means loss of prime.

Nothing is wet with no visible leaks.
Engine cranks over fine.
After it has ran it starts fine.
Happens after sitting a while after a longer drive. And so far never in my driveway just when I am somewhere it can strand me, ha.

If you have recommendations on how to section test the fuel system for leaks that would be very helpful. I have this afternoon so will be throwing the mighty vac on it and hopefully finding something. Thanks for the replies and help by the way.

pyromancer said:

Nothing is wet with no visible leaks.
Engine cranks over fine.
After it has ran it starts fine.
Happens after sitting a while after a longer drive. And so far never in my driveway just when I am somewhere it can strand me, ha.

If you have recommendations on how to section test the fuel system for leaks that would be very helpful. I have this afternoon so will be throwing the mighty vac on it and hopefully finding something. Thanks for the replies and help by the way.

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Here is a quote from another no start thread I replied to. I just diagnosed and solved the no start issue for a friend, in the work parkinglot:

KrashDH said:

Just a tip on when you get to this.
I just went through diagnosing a friend's Golf TDI with a no start issue. She had the top end seals of the pump replaced from a Euro mechanic (but not TDI specific). They did not go as far as replacing the head seal though unfortunately, which it's still leaking from there.
She had let the car sit a couple months and there was the no start. She was wicked frustrated with the car, was about to sell it for damn near next to nothing. I told her to let me play with it for a bit. So in the work parkinglot, I used a mighty-vac and pulled vac through the filter to make sure fuel was getting through the filter.
Then tried pulling vac from the IP return line. I couldn't get fuel up to it, even after pumping for 30 min +. I figured we'd try to crank it anyway and crack the injectors to see if we could get fuel. It basically was pooling fuel at the injector nut interface, not squirting up, so I knew we still didn't have a good prime, which led me to believe air was getting in the system still.
So I tried priming with the injector return line (attached to the IP) and was able to just barely start seeing fuel there after pumping for about a minute. This was a good sign, but it still wouldn't make it all the way into the mighty vac cup. This solidified that air was getting in the pump somehow, but that the leak was not that bad.
We re attached the injector return line and then cracked each injector nut while cranking and they started spurting fuel up high. After they were all tightened, car fired up, ran rough for about 5 seconds, then smoothed out. Then watched the pump to see if it was leaking, and there was 1 drip every 20-30 seconds coming out the back around the bottom of the head, so my theory was confirmed.
Advice, if you're having trouble priming, use that injector return line instead of the IP return line

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While the car is running, check for any slow drips from around the IP head, also around the corner of the IP on the bottom towards the block. Hers was leaking 1 drop every 20-30 seconds. If there is no visible leak coming from there, I would suspect the "T" or the o rings on the return T. If you can pull fuel easily through the IP return line, then it would tell me your pump is sealed well. I couldn't pull fuel for the life of me through the IP return line for my friend. I was able to do it from the injector return line though because the ID was smaller, and her leak was not that bad.

If that all passes and you prime that pump, then you really need to find a buddy to crank while you crack the injectors. Air is getting in there somehow, there's only usually a few ways it can get in there.

Look atop the fuel pickup in the tank, there is an access plate under the RR seat bottom. Check for any dampness there.

Hey OP,
Over the winter I had my car sit for about 2 weeks with a no start condition.
This past winter it was below freezing temps for many days straight which caused the I/P head seals to shrink which in turn let air into the fuel system.
The IP seals were my culprit when i had a crank no start on my 02 ALH.
I wasnt able to pull any fuel with a vacuum pump either...
Like Oilhammer asked. . . . Do you notice any pattern when it decides not to start?

+2 on replacing the breather Tee fitting on top of your fuel filter. I believe its a $5.00.. Worth replacing if you haven't and especially if you live in a cold climate. They're known to crack; there is an o-ring there too, if that's dried up it could let air in. Cheap insurance.

Also, when you replace it, grease the O-Ring.

It sucks when its intermittent.. Goodluck

Hoped in and started up first crank. Of course never an issue while at home.

I shoved some blue shop towels around the pump and am letting it idle for a bit. No wetness around the fuel pickup under the rear seat.

https://m.youtube.com/watch?feature=youtu.be&v=X74w9omjjaA

Let it run until up to temp. No wetness on the towels. Did notice a nice stream of bubbles in the clear line when it was up to temp.

https://youtu.be/J5RCi9uJD18

pyromancer said:

Nothing is wet with no visible leaks.
Engine cranks over fine.
After it has ran it starts fine.
Happens after sitting a while after a longer drive. And so far never in my driveway just when I am somewhere it can strand me, ha.

If you have recommendations on how to section test the fuel system for leaks that would be very helpful. I have this afternoon so will be throwing the mighty vac on it and hopefully finding something. Thanks for the replies and help by the way.

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I had this happen at one point with my MkIV, but it was VERY specific.

Start car, pull out into the driveway, shut it down, it was VERY hard to restart.

Drive it a mile or two, or longer, it's fine. Overnight, fine. Sit a week, fine.

It was an airleak -- but it was NOT easy to find. It turned out to be in the "T" and it let just enough air in that if you started and ran it and then shut down "just right" you'd get the bubble in the IP and it wouldn't start.

Once I found and fixed it, no more problem.... they can be damnably hard to find.

I suppose one thing you could try to do (determining if it's the T connection) is wiggle the T ever so slightly (with the mickey mouse clip in place) and see if it introduces more bubbles into the clear line. I know on my Golf although there are a few bubbles here and there in the clear line when running, there's not as many as you have in that video. If your T isn't cracked, it's likely the 2 o-rings that are letting air past.

New T came today. Didn’t fix the issue. Idolated the filter to make sure the leak wasn’t there. Then pulled the lines from pump to filter and isolated and tested each one. Put Vacuum directly on the pump outlet. It seems to not hold vacuum past 12 on the mighty vac. My question now is there a way to isolate the pump from the injector lines so I can determine if my leak is the pump or a line? I could pull each line individually but really want to know if there’s some better way? Also how hard is reasealing the pump if that’s the issue? Thanks.

https://m.youtube.com/watch?v=NBaJznlwM78

Re read my post #9. Your vac pulling from the return line on the IP looks like it yielded identical results to when I worked on my friends car.

Pull the return line from the injector (leave it connected to the pump). It's a small 3mm ID line.

Plug your IP return line with your finger, or a bolt. While doing so, pull vac on that small injector return line connected to the pump. You are pulling up through the injector return (up through the IP), so you're isolated from the injectors.

Your vac will slowly go down in either circumstance, whether you're moving fuel or air is introduced.

It's just odd you have no pump leaks.

The only other thing I can think of is maybe one of your injector lines isnt seated properly, or cracked.
While it's running maybe spray some soapy water on the injector line/ nut area and watch for bubbles.

There is a GREAT 7 part YouTube on how to do the IP seals on the car. It's not a hard job, but you haveto be meticulous, and careful. It takes a bit of time.

https://www.youtube.com/watch?v=VR44StvcXms&list=PLUNS-IqlfxwCxLPoYGeI_-E_O_dsBkDp1&index=1

KrashDH said:

Re read my post #9. Your vac pulling from the return line on the IP looks like it yielded identical results to when I worked on my friends car.

Pull the return line from the injector (leave it connected to the pump). It's a small 3mm ID line.

Plug your IP return line with your finger, or a bolt. While doing so, pull vac on that small injector return line connected to the pump. You are pulling up through the injector return (up through the IP), so you're isolated from the injectors.

Your vac will slowly go down in either circumstance, whether you're moving fuel or air is introduced.

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Krash in which video? Because if you look at the last one I have the lines pulled and am plugging the inlet with my thumb to see if I can hold a vacuum. If you look at previous video with the inlet attached I can pull fuel through the return line. With the hoses conected, I get air bubbles from the return but I can fill the mighty vac cup.

I can pull from the 3mm line in the morning but imagine it will pull fuel. If there’s no bubbles from those lines would it mean the lines are fine? If there are bubbles would it mean I have a bad line?

My reason for disconnecting lines was to find something to make pressure on the mighty vac drop. Narrow down where air is getting in. It seems like there had to be something letting air in the pump or hoses. If it’s all sealed with it isolated like that the pressure shouldn’t drop right? Sounds like you’re saying that isn’t the case. So I’m not understanding how I would isolate a leak to the pump by doing what you suggest if you’re telling me vac is going to drop no matter what. I have no physical leaks. I’m just trying to figure out where it is sucking in air. I isolated the filter with the T in it holds at 20. I Isolated the lines they hold at 20. I could pull all the 3mm injector returns and do the same. Would rather not, but I really want to find this damn leak and am not sure what else to do.

https://youtu.be/AHzDDCjOT7Y

First thing this morning starts and runs fine. No air in lines. Once it warms up I see air in the clear lines moving through.

https://youtu.be/sQm-TGkD8ek

Applying vacuum at 3mm line. Holds at 20 and doesn’t pull fuel. Not sure what that means, again would love explanation please.
https://youtu.be/_QPlGQZXCzs

So they don't leak, good. Their only purpose in life is to catch the excess fuel going to the injectors, with the car off you wouldn't get fuel.

BobnOH said:

So they don't leak, good. Their only purpose in life is to catch the excess fuel going to the injectors, with the car off you wouldn't get fuel.

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Doesn’t that mean a leak would have to be at my pump?

Maybe another way of asking would the pump not hold a vacuum if I plugged the inlet and applied vacuum to the return? Because it doesn’t for anything over 12Hg. KrashDH’s comment has me confused on if that test actually told me anything.

Thanks for the videos, you def have a hard one to track down. The leak you're chasing is likely very small. Not enough to lose prime overnight to have elongated cranking times, but it's big enough to pull air in while the pump is drawing fuel through the system.

You replaced the "T" and o-rings, and filter...while the car is running, if you "wiggle" that T, does it introduce more bubbles, less bubbles, or doesn't have an effect?

By chance while it's running, did you try soapy water on the injector nuts and lines to see if it's coming through one of those connections?

Edit...you posted that 3rd video of the injectors holding vac after I wrote this so the soapy water isn't going to tell you anything

pyromancer said:

Doesn’t that mean a leak would have to be at my pump?

Maybe another way of asking would the pump not hold a vacuum if I plugged the inlet and applied vacuum to the return? Because it doesn’t for anything over 12Hg. KrashDH’s comment has me confused on if that test actually told me anything.

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I think you're confusing your troubleshooting here. The last video that you had the pump connected to the 3mm line, that's only going to tell you about the injector lines. Nothing about the pump. But it should tell you the lines are fine

The video of you pulling through the IP return line where you said you were "getting fuel" I'm not convinced. You should have filled the lines with the mighty vac, with maybe a few air bubbles. But you should get solid fuel out of there. Your video shows a lot of air bubbles coming out that are created with a tiny bit of fuel. Not being able to get the return line above 12-15 is the same thing that happened on my friends car. Then it would go down pretty fast, and never get fuel out of there. Maybe some "bubbles" like yours. Her head pump seal was leaking.

With all the lines connected, I was trying to tell you to do reverse of the last video. Unplug the injector return line from the injector, leaving it connected to the pump. Then try pulling fuel up through that way. you won't hold complete vac as you will be moving fuel. The vac will go down slowly as it draws fuel up through there. If you can get fuel up that way, and not the other way, there is some sort of leak in the pump.

If your pump was completely dry, then you could test it to hold vac. But if there's fuel in it at all, that gauge will move as you displace the fuel.

Here's the other thing you need to do though. You could just have a trapped air in the system that moves around randomly. Once your IP is primed and you know you have fuel in it, crack your injectors one by one and make sure that your lines are completely purged of air. Tighten the injector nut while cranking is happening ensures that no air back purges into the system. So put paper towels down because there should be a high pressure spurt that comes out of the injector while cranking.

If there is a bubble in the middle of the system, it will work it's way up there through the injectors. You want nothing but fuel at the injectors.

pyromancer said:

Doesn’t that mean a leak would have to be at my pump?

Maybe another way of asking would the pump not hold a vacuum if I plugged the inlet and applied vacuum to the return? Because it doesn’t for anything over 12Hg. KrashDH’s comment has me confused on if that test actually told me anything.

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I think you've shown is pulling air, but it could be anywhere from the tank forward. Krash has good comments. Check in sections. Never done this but it might be more conclusive to put a few pounds air pressure just on the pump, see if it blows fuel.

https://youtu.be/ZFi4GC2uEbI

Wiggling the T and soapy water. Wiggling might cause a few more bubbles but hard to tell.

KrashDH said:

With all the lines connected, I was trying to tell you to do reverse of the last video. Unplug the injector return line from the injector, leaving it connected to the pump. Then try pulling fuel up through that way. you won't hold complete vac as you will be moving fuel. The vac will go down slowly as it draws fuel up through there. If you can get fuel up that way, and not the other way, there is some sort of leak in the pump.

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But if I read the above correctly this means I have a leaking pump correct?
https://youtu.be/BYVp3YgtYwo

We're not going to be able to tell for sure on this interweb thang.
If the pump leaks, you might expect to see sign.

pyromancer said:

https://youtu.be/ZFi4GC2uEbI
Wiggling the T and soapy water. Wiggling might cause a few more bubbles but hard to tell.
But if I read the above correctly this means I have a leaking pump correct?
https://youtu.be/BYVp3YgtYwo

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The fact that you can draw fuel through the 3mm line but cannot through the IP return would signify to me that you are not getting a good seal on your pump. Drawing through a smaller volume allows you to actually prime the pump if there is a leak, for people that are struggling to do so from the IP return line. Gives them fuel in the pump so they can then crack the injectors and bleed the lines. Which would be my next step in your case.

That T still does not look like it's sealing well to me. Notice that there tends to be very few air bubbles until you wiggle it? It doesn't look like the o-rings are doing their job very well. Did you add a dab of grease to them when you installed?

BobnOH said:

We're not going to be able to tell for sure on this interweb thang.
If the pump leaks, you might expect to see sign.

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Exactly right, I think I've exhausted my internet help on this one without being able to get my hands on the car.

KrashDH said:

The fact that you can draw fuel through the 3mm line but cannot through the IP return would signify to me that you are not getting a good seal on your pump. Drawing through a smaller volume allows you to actually prime the pump if there is a leak, for people that are struggling to do so from the IP return line. Gives them fuel in the pump so they can then crack the injectors and bleed the lines. Which would be my next step in your case.
That T still does not look like it's sealing well to me. Notice that there tends to be very few air bubbles until you wiggle it? It doesn't look like the o-rings are doing their job very well. Did you add a dab of grease to them when you installed?
Exactly right, I think I've exhausted my internet help on this one without being able to get my hands on the car.

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I can draw through the return line to the filter. I get air just like through the small injection line. Said that a few times. It’s how I have been priming the pump after I do this stuff each time.

I have greased the T. Have tried two filters and two Ts greasing each.

I don’t have help is there a way I can crack the injectors without someone to crank over.

pyromancer said:

I don’t have help is there a way I can crack the injectors without someone to crank over.

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No this is a 2 person job because as soon as it starts spurting up, the person at the injector needs to tighten the nut down while the cranking is still happening or air will get right back in the system.

You could have someone help you at work, do you drive to work? That's how I helped my friend out, we did it all in the parking lot.

To your point about drawing fuel through the IP return line, unless you have a better video, the one you showed did not show fuel coming up through the return line. All I saw was air bubbles and no fuel. But maybe I missed one. You should be able to get 20+ vac on that return line if there are not leaks and then it will drop as fuel moves.